Forstner bit speed calculator
The drill press speed for a Forstner bit by its diameter, in hardwood or softwood. It takes the median of three published charts, a bit maker's, a drill press maker's and Fine Woodworking's, and shows each one. The speed that comes with your bit always comes first.
Drill press speed
700 RPM
Median of 3 sources
The speed from your bit’s maker comes first.
Why: For a 1 in Forstner bit in hardwood, the median of 3 charts is 700 RPM (they span 500–1,250). The speed from your bit’s maker comes first.
Why these numbers?
The situation
A 1 in Forstner bit in hardwood.
From your input: bit diameter and wood
What that means
Infinity Cutting Tools 700, Fine Woodworking 500, Grizzly 1,250 RPM.
The number
The rim of the bit at 700 RPM moves π × 1 × 700 ÷ 12 = 183 ft/min.
Arithmetic: exact by definition
Sources
- Infinity Cutting Tools, Forstner Bit Speed & Feed Chart (HSS Forstner bits, hardwoods and softwoods, 3/8" to 2"), read 2026-11-07
- Fine Woodworking, Drill press speed chart: Forstner bits, softwood (pine) and hardwood (hard maple), read 2026-11-07
- Grizzly, G7943/G7947 drill press manual: drill bit speed chart, spade/Forstner bits (a guide; the bit maker’s speed comes first), read 2026-11-07
Forstner bit speed chart
The charts disagree widely for small bits: Grizzly's drill press chart allows 1,500 RPM in hardwood up to 1/2 in, where Fine Woodworking's says 500 to 700. That is why each answer shows its tier and the calculator names every chart. Infinity's chart starts at 3/8 in, so the 1/4 in row rests on two charts.
| Bit Ø | Hardwood | Softwood | Basis (hardwood) |
|---|---|---|---|
| 1/4 in | 700 | 2,200 | Two sources disagree: Fine Woodworking 700, Grizzly 1500 |
| 3/8 in | 1,000 | 2,000 | Median of 3 sources |
| 1/2 in | 900 | 2,000 | Median of 3 sources |
| 5/8 in | 900 | 1,500 | Median of 3 sources |
| 3/4 in | 900 | 1,500 | Median of 3 sources |
| 7/8 in | 700 | 1,500 | Median of 3 sources |
| 1 in | 700 | 1,500 | Median of 3 sources |
| 1 1/4 in | 700 | 1,000 | Median of 3 sources |
| 1 1/2 in | 600 | 800 | Median of 3 sources |
| 1 3/4 in | 400 | 600 | Median of 3 sources |
| 2 in | 350 | 500 | Median of 3 sources |
What the charts agree on
Grizzly: its chart is a guide; always follow the bit maker’s speed when the bit comes with one.
One source: Grizzly, the maker of that drill press , sources [1]
Bigger Forstner bits run slower, and hardwood slower than softwood: every chart here steps down both ways.
Sources
- Grizzly, G7943/G7947 drill press manual: drill bit speed chart, spade/Forstner bits (a guide; the bit maker’s speed comes first), read 2026-11-07
- Infinity Cutting Tools, Forstner Bit Speed & Feed Chart (HSS Forstner bits, hardwoods and softwoods, 3/8" to 2"), read 2026-11-07
- Fine Woodworking, Drill press speed chart: Forstner bits, softwood (pine) and hardwood (hard maple), read 2026-11-07
Drill bit sizes, pilot holes and countersinks are in the Fasteners and drilling section.